The present invention relates to the field of safety and of the fight against or prevention of theft, aggression or breach of close and burglary. Its subject matter is a method of and a device for the permanent self-acting bolting or locking of a movable member in a supporting framework or like structure, said device being tripped or set into operation in case of breach of close or assault. The invention is mainly applicable in safes and strong-boxes or strong-rooms and safety-vaults.
In the following, the invention will be mainly illustrated by setting forth the technical problem to be solved in the case of its preferred application, mainly the relocking of safes and strong-boxes or of strong-rooms and safety vaults upon an attempt at breaking the same open.
The doors of safes or of strong-rooms are generally armoured on the inside and on the outside by means of several millimetres thick steel sheets. The space left between both metal sheets may be filled with steel elements of various shapes embedded in concrete. Such an assembly provides an effective protection against the flame of a cutting torch or against an attack with a hammer-drill or a rotary drill or borer.
To provide against the attacks, there has already been provided automatic locking or bolting systems which would lock all the closing lock-bolts or latches with the assistance of means such as dogs, keeps or stops. The dogs are moved by a complicated and expensive mechanical control system. For instance, for a small safe the volume of which is of 500 cm.sup.3, there may be four lock-bolts on each vertical standard, upright or post and two lock-bolts on each horizontal line. The locking arrangement may comprise two sliding dogs co-operating with both pairs of vertical lock-bolts, respectively, and a dog acting upon the pair of upper horizontal lock-bolts as well as another dog acting upon the pair of lower horizontal lock-bolts.
The approach made to the locking problem has not been satisfactory heretofore because the mechanical operating systems are complicated and costly.
In the art of safe and strong-box constructions have already been used so-called "detector" means which, when the safe is attacked, are likely to operate a movable element which would relock the safe to closed position by acting for instance upon the lock mechanism.
Thus are already known detector means consisting of a simple wire connected to a spring-biased finger and which when it is broken under the effect of the attack would release or free the finger which thus would relock the safe.
Such detector means, however, are not always satisfactory to the extent where the burglars may cut out not only the lock-bolts of the safe but also the movable finger of the detector so that the present systems for relocking in case of attack do eventually not really secure a final locking of the safe in the closed condition.
The U.S. Pat. No. 1,850,337 discloses a safety device applicable to a safe door. In case of an attempt at violation, a gas-controlled triggering system would operate catch pins or lugs effective to set in or fix the door. The gas is preferably the same as the one conventionally used with incapacitating or disabling effects. This old patent (1930) describes a closure system with locks working under the action of a gas under pressure and under a mechanical control. Such a system allows only for a provisional increase in safety because it would still be possible to cause the lock or locks to move back into the initial position. The U.S. Pat. No. 1,850,337 does not provide for a final and permanent locking. Moreover, the detection means are not appropriate to provide for an other than mechanical control of the system.